A223600 Petersen graph (8,2) coloring a rectangular array: number of 2 X n 0..15 arrays where 0..15 label nodes of a graph with edges 0,1 0,8 8,14 8,10 1,2 1,9 9,15 9,11 2,3 2,10 10,12 3,4 3,11 11,13 4,5 4,12 12,14 5,6 5,13 13,15 6,7 6,14 7,0 7,15 and every array movement to a horizontal, diagonal or antidiagonal neighbor moves along an edge of this graph.

256, 256, 1504, 6736, 32768, 156592, 755200, 3643024, 17608064, 85179184, 412367104, 1997306896, 9677417600, 46900761520, 227339596288, 1102103488912, 5343259128704, 25906912147504, 125615423519488, 609091866864400

Offset

1,1

Comments

Row 2 of A223599.

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 6*a(n-1) + 3*a(n-2) - 42*a(n-3) - 8*a(n-4) + 48*a(n-5) for n>6.

Empirical g.f.: 16*x*(16 - 80*x - 50*x^2 + 481*x^3 + 40*x^4 - 456*x^5) / ((1 + 2*x)*(1 - 8*x + 13*x^2 + 16*x^3 - 24*x^4)). - Colin Barker, Aug 21 2018

Example

Some solutions for n=3:
..2..3..4...11..3..4....0..8.14...15..7..0...15..9..1....3..4..3....9.15..7
.11..3..2....4..3..4...10..8.10....0..7..0...11..9.15....5..4..5...13.15..9

Crossrefs

Cf. A223599.

Sequence in context: A186474 A093861 A248776 * A217848 A044872 A044979

Adjacent sequences: A223597 A223598 A223599 * A223601 A223602 A223603

Keyword

nonn

Author

R. H. Hardin, Mar 23 2013

Status

approved